A conventional hook is an S-shaped hook 1, as shown in FIG. 1. The S-shaped hook 1 is constituted by two side-hook portions 11, with their openings being disposed upside down. Therefore, the side-hook portions 11 with different openings can be used to hang up an object. The application of the S-shaped hook 1 is very broad, such as in drying clothes, in camping or on an advertisement banner. However, when the S-shaped hook 1 is hung up on a rope 12, as there is no acting point to the S-shaped hook 1, the S-shaped hook 1 will slide freely on the rope 12. Furthermore, if the rope 12 itself is inclined to an end, then the entire S-shaped hook 1 will be shifted to the inclined end and cannot be secured on a fixed point. Therefore, it is rather tedious to use the S-shaped hook 1.
In addition, to improve the shortcoming in the S-shaped hook 1, a clamp 13 is sold on the market. Referring to FIG. 1 again, by the elasticity of a spring, clipping pieces 131 at two sides of the clamp 13 are tightened toward the center to clamp clothes or an object. Therefore, the clamp 13 can be secured on a fixed point of the rope 12. In using the clamp 13, the clipping pieces 131 have to be extended outward first and then the clothes or object can be fixed between the clipping pieces 131. Thus, it is time and labor consuming, and it will result in an unrecoverable clamp mark on the clamped clothes or object, thereby damaging the clothes or object. Furthermore, as the clamp 13 is usually made of plastic, the spring will drop out and the clipping pieces 131 will be embrittled and fractured easily after a long time of use, which shortens the lifetime of use of the clamp 13. Therefore, a metallic (iron) clamp 13 arises. Although, the clipping pieces 131 will not be embrittled, they can be corroded to affect the clamped clothes or object, which is still not perfect in using the clamp 13. To avoid corrosion to the metal (iron), a stainless steel clamp 13 is further developed. Although, the clipping pieces 131 will not be corroded, the cost of the stainless steel clamp 13 is higher and the stainless steel clamp 13 is heavier, which is not economically efficient. On the other hand, although the clamp 13 can be positioned on the rope 12, its use is easily limited in space and site that it cannot clamp the clothes or object freely.
The present inventor is specialized in the research, development and manufacturing of all kinds of camping equipment, outdoor products or houseware, and is therefore very aware of the shortcoming in using the conventional S-shaped hooks and clamps that they are not in compliance with the needs in camping, outdoor activities or household use. Accordingly, by the expertise and many years of work experience of the present inventor, the present invention has emerged after many times of correction, testing and improvement.